1. Field
Exemplary embodiments of the present invention relate to a semiconductor design technology and, more particularly, to an internal voltage generation circuit.
2. Description of the Related Art
Semiconductor device operations require various internal voltages. The semiconductor device has voltage generators for generating the internal voltages. The semiconductor device may include a voltage generator for boosting a power supply voltage VDD that is supplied from an external device to generate a pumping voltage VPP having a voltage that is higher than the power supply voltage VDD. The voltage generator includes a DC/DC converter such as a charge-pump regulator.
One example of a semiconductor device that has a voltage generator is an image sensing device. Image sensing devices use the pumping voltage VPP in lieu of the power supply voltage VDD to improve operational reliability. For example, the image sensing device generates an operation control signal, which is used to transmit a photo-electric charge accumulated in a photodiode to a floating diffusion node, based on the pumping voltage VPP. When the photo-electric charge is transmitted to the floating diffusion node, the operational reliability of the image sensing device may be improved as the transmission capability is improved.
An image sensing device captures images using the photosensitive properties of semiconductors. Image sensing devices may be classified into charge coupled device (CCD) image sensors and complementary metal oxide semiconductor (CMOS) image sensors. The CMOS image sensors have come into widespread use as the CMOS image sensors allow analog circuits and digital control circuits to be directly implemented on a single integrated circuit (IC).